Stack valve of water gas generators and the like



June 21, 1949. F. A. MacGREGOR 2,474,111

7 STACK VALVE OF WATER GAS GENERATORS AND THE LIKE Filed July 24, 1945 2 Sheets-Sheet l \llae m rK- i' W W I June- 21, 1949. MacGREGOR 2,474,111

STACK VALVE OF WATER GAS GENERATORS AND THE LIKE Filed July 24, 1945 2 Sheets-Sheet 2 Patented June 21, 1949 STACK VALVE OF WATER GAS --GENERA- TGRS AND THE LIKE Frank Alexander MacGregor, WestminstefiEngland, assignor to Humphreys & Glasgow Limited, Westminster, England Application July: 24, 1945, Serial'No;-606,778 In Great Britain August 9, 1944- 7 Claims.

This invention-has reference to stack valves of water gasapparatus and the like which are adapted to act as safety or pressure release valves.

The object-of, the invention is to enable such a valve to be moved to and-frornits seat with less l power or manual effort by comparatively-light operating gear.

\ According to the 'inventionthe valve, which is only asheavy as-isx-required for strength and resistance to distortion, is opened and closed through the medium of a bell crank arrangement adapted to impart during the initial valve-open.- ing movements, when the mechanism is gaining momentum, "only slight movement to the valve and the valve hasapplied to it during the latter part of the closingmovements, preferably when ithas reached its seating, a load chosen according to the pressure at which the valve is to lift. The va1ve,'which is coupled to a bell crank is carried by wheels running on tracks which extend laterallyfrom the stack and are so arranged relatively to a loaded member that, during the latter part ofthe closing movement of the bell crank,the load is caused to act on the valve and that during the initial part of the valve-opening movement the load on the valve is relieved.

In the accompanying drawings, Figs. 1 and 2 are diagrammatic side elevations of one arrangement showing the stack valve in the closed-and open positions respectively.

Figs. 3 and 4 *aresimilar' viewsof another arrangement.

Referring-t Figs. 1 and 2; a isthe stack formed with a setting a for the valve 1).

At the sides of the valve seating are parallel tracks 0 extending well beyond the seating; a pair of wheels (1 run on the tracks and are mounted on an axle e to which is fixed an arm I jointed to a bell crank lever g pivoted at h at the outer end of the tracks and connected by a rod i to an automatic operating device or operating hand lever (not shown). To the ends of the axle e are fixed other arms is fitted at their ends with rollers Z lying beneath levers m fulcrummed in uprights n extending from the tracks 0; the levers m are formed with cam paths m for the rollers and have suspended from them loading weights 0. The weights 0 are shown suspended from the levers m by rods 0; o are supports on which the weights rest when the valve is in the open position. The valve 17 is pin jointed to the axle arm f at b between the axle of the wheels and the pin which joints the axle arm f to the bell crank g. The wheel tracks 0 are mainly horizontal and preferably have a rising part c towardstheouter-ends to-impart a braking effect at the endof the valve opening movement and to assist the commencement of the valve closing movement.

ln-one extremeposition of the bell crank g, the valve b is supported clearof its seating 11 and, by movement of the bell crank, the valve will be caused to approach its seating, and it is arranged that lit willreach the seating b'efore'the bell crank has completed its angular -movement. In the preferredarrangementas shown in Figs. 1 and 2, continuation of the angular movement of the bell crankwill-cause the arm 1 to-pivot about the pin at'b' jointing it to the-valve, and the wheels dtogetherwith their axle and the arms is with rollers l will be'r-aised and lift the cam path levers m and depending weights 0, all of which will contribute to theload on the valve. The contour of the-campaths mf, and the angle between the roller-carrying. arms is andthe axle arms 1, are so chosen as try-give the desired rate-of lifting ofthe weights -0' attached to'the cam path levers when thelatter arecontacted by the rollers. This lifting of the Weights has a braking effect on the mechanism.

In opening, this sequence of movements is reversedand, instead of a braking action, the weights-have an accelerating action on the mechanism at the-start of the "opening movement and as-the wheels 01 travel'upthe slope c the movement is slowed down.

\ Arrangements according to the present invention are applicable in cases where a portion or section'of-the:stack -pipe'or casing is movable to expose the valve when it is closed as described in our former British application for Patent Serial No. 14,102 of 1944; the movable portion or section may be detachably coupled to the axle e and, part of the weight of the portion or section will contribute to the load on the closed valve.

In the modified arrangement shown in Figs. 3 and 4 the valve b is carried on the axle e of the wheels (1. The rollers l which coact with the cam paths of the loaded levers m are also mounted on the axle e and the wheel tracks 0, instead of being horizontal near the point corresponding to closure of the valve, slope downwards at c to permit the valve to descend on to its seating.

The arrangement shown in Figs. 1 and 2, may be modified by mounting the weight lifting rollers Z on the axle e of the wheels d and the arrangement shown in Figs. 3 and 4 may have the rollers Z mounted on arms fixed to the wheel axle e as shown in Figs. 1 and 2.

Where the stack valve is mounted on the axle 3 of the wheel as in Figs. 3 and 4, the valve, during its final closing movement, is caused to slide on its seat thus cleaning it.

As will be understood, loading by means of springs instead of weights may be adopted, though weights are less liable to damage and give a more positive and fixed load.

What I claim is:

1. A stack valve which is carried by wheels running on tracks extending laterally alongside the stack and wherein an arm that is fixed to an axle on which the wheels are mounted 1s jointed to a bell crank and has the valve jointed to it intermediate of the axle and bell crank, other arms being fixed at an angle to the arm carrying the valve and in such relation to loaded levers formed with cam paths that, during the latter part of the valve closing movement, the said arms raise the loaded levers, the angular movement of the bell crank being such that, after the valve has reached its seating, the wheels are lifted from the tracks by the arm to which the valve is jointed being caused to pivot about the pin attaching the valve to it.

2. A stack valve which is carried by wheels running on tracks extending laterally alongside the stack and wherein the valve and rollers which coact with cam paths on loaded levers are mounted on the axle of the wheels, the wheel tracks sloping downwardly near the point corresponding to the closing of the valve to permit the valve to descend on to its seat.

3. The combination of a stack having a valve seating, tracks extending laterally alongside the stack, wheels running on the tracks, an axle on which the wheels are mounted, an arm fixed to the axle, a bell crank one arm of which is coupled to the said axle arm, an operating rod connected to the other arm of the bell crank, a stack valve jointed to said axle arm intermediate oi the axle and bell crank, other arms fixed to the axle at an angle to the aforementioned axle arm, loaded levers extending over the paths of said arms the axle arm and bell crank being such that operation of the bell crank moves the wheels and valve towards and from the valve seat and that, during the latter part of the valve closing movement, the said arms raise the loaded levers, the angular movement of the bell crank being such that, after the valve has reached its seating, the wheels are lifted from the tracks by the arm to which the valve is jointed being caused to pivot about the joint.

4. A stack valve for water gas generators or the like, adapted to act as a safety or pressure relief valve, comprising valve-supporting means movable towards and from the valve seat, a weight device adapted to act upon the valve and adapted to be lifted by the valve-supporting means when the valve approaches its seat; tracks extending laterally from the stack; said valve supporting means including a Wheeled axle movable on said tracks; means for moving the axle on said tracks; said weight device including a normally inactive loaded lever adapted to be raised by a member on the valve supporting means during the latter part of the valve closing movement and prior to valve seating; and said tracks being disposed at a lower elevation than the wheels when the valve is seated.

5. In a stack valve as set forth in claim 4, said lever being released during the initial portion of the valve opening movement.

6. In a stack valve as set forth in claim 4, a bell crank lever fixed to said axle, one armof which pivotally carries the valve and the other arm of which is adapted to contact the underside of the lever; the arms being disposed at such angles that during the latter part of the valve closing movement the first arm will raise the lever, and after the valve has been seated the wheels will be lifted from the tracks by the second arm to which the valve is jointed being caused to pivot about the valve pivot.

7. In a stack valve as set forth in claim 4, said axle carrying said member adapted to contact the underside of the said lever, and said valve being carried directly by the said axle, whereby during the latter part of the valve closing movement the member will raise the lever; and said tracks sloping downwardly near the point corresponding to the closing of the valve to permit the valve to descend onto its seat and the wheels to leave the tracks.

FRANK ALEXANDER MACGREGOR.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 770,623 Zander Sept. 20, 1904 V FOREIGN PATENTS Number Country Date 25,474 Great Britain Aug. 4, 1910 

